US6099518A - Needle herniorrhaphy devices - Google Patents

Abstract

Guidewire-deliverable devices and methods of using the devices for separating adjacent layers of tissue and for delivering a surgical prosthesis to an operating site. A guidewire-delverable cannula provides an elongate window for accessing the operating site with a tissue-separating device. The tissue-separating device may include one of several types of an inflatable balloon or a tissue-dissecting member. The tissue-separating balloon may simultaneously deliver the prosthesis during tissue separation and may further be detached to remain with the prosthesis over the operating site. Alternatively, the prosthesis may be separately provided after the adjacent layers of tissue have been separated.

Description

FIELD OF THE INVENTION

The present invention relates generally to methods and devices used to form an operating cavity between adjacent tissue layers of a patient. More specifically, the present invention relates to devices which may be percutaneously inserted into the body through a small diameter cannula and expanded between adjacent layers of tissue to provide an operating cavity in registry with an operating area and to provide a prosthesis to facilitate, for example, groin herniorrhaphy.

BACKGROUND OF THE INVENTION

Groin herniorrhaphy is among the oldest and most common surgical procedures performed. Unfortunately, the average operative result is beset by a period of discomfort with resultant disability. Techniques have been developed, such as laparoscopic herniorrhaphy, with the intent to reduce morbidity and recurrence rates. Most trials, however, have noted only a moderate improvement in the pain and disability associated with the procedure. Further, the added cost of equipment, the need for general anesthesia, and the additional operating room time required for this procedure indicates that it is less than ideal. There continues to be a need in general surgery for a procedure that can effectively address all the considerations of cost, disability, and hernia recurrence for patients with an inguinal hernia.

Failure of the transversalis fascia to retain the peritoneum from penetrating the myopectineal orifice is the fundamental cause of all groin hernias. Historically, hernias were repaired by stretching the transversus abdominis tendon across the myopectineal orifice and suturing it to the inguinal ligament. This technique and its current modifications rely upon the surgical approximations of edges of the defect to cover the myopectineal orifice. Such a technique, however, results in a distortion of the groin anatomy which creates stress on both the suture upon which the hernia repair is dependent and on the tissue planes that have already demonstrated their inherent weakness by the presence of a hernia. It is believed that the tension placed on the suture line as a result of the unnatural approximation of the tissues leads to recurrence, especially early recurrence.

A relatively modern technique to effect hernia repair is to place a prosthetic mesh over the myopectineal orifice. This technique enlists the intra-abdominal pressure to secure the inlayed prosthesis to the pelvic floor rather than allowing it to act as a factor in recurrence of the hernia. After mesh placement, the peritoneum becomes nondistensible, so there is no need for hernia defect closure. An effective modification of this technique is to place a polypropylene mesh on the outside of the myopectineal orifice. The prosthesis is sutured to the adjacent tissues with a minimum of tension. This repair has proven effective in preventing both short- and long-term recurrence. In addition, the pain associated with this operation is less than with other open operations. Its single disadvantage is the required division of tissue to gain access. The operation is commonly performed under local anesthesia with sedation. Hospitalization is avoided and most patients return to work as rapidly as those experiencing the laparoscopic preperitoneal herniorrhaphy.

Several mechanisms of hernia recurrence have been identified, such as the use of an inadequately-sized prosthesis so that the entire myopectineal orifice is not covered. Related to this concept of an inadequately-sized mesh is the possibility of inadequate overlap. It is felt that all defects should be overlapped by at least 2 cm if the mesh is stapled and by 3 cm or more if not stapled. For example, the myopectineal orifice measures approximately 10 cm×8 cm in an adult so a 16 cm×14 cm mesh is required.

While the placement of a prosthetic mesh in the preperitoneal space is currently performed with either a laparoscopic or an open technique, it is desirable to perform the procedure by placing small needle cannulas in the groin to dissect the preperitoneal space. Visualization would be obtained with a 2 mm laparoscope placed through one of the cannulas. The hernia sac would be dissected free and ligated. A prosthetic mesh would thereafter be placed to reinforce the transversalis fascia. The patient would have reduced pain and disability as currently is associated with the procedure. In addition, the need for general anesthesia could be eliminated.

Such a needle herniorrhaphy technique requires a device for creating an operating space in registry with the myopectineal orifice. The device should be insertable through the cannulus of a needle. The device should further be either retrievable through the cannulus of the needle after creating the operating space or biodegradable so that it may be left in place over the herniated region.

Such a needle herniorrhaphy technique also requires a prosthesis employing a thin surgical support mesh that may be rolled or folded and thereafter inserted within the cannulus of a needle. The mesh should also be non-linting, fray resistant, and ravel resistant. The mesh must be sufficiently porous to allow for tissue growth through the graft after implantation. The healing tissue grows through porous openings in the implanted mesh, thereby assimilating the mesh and adding structural integrity to the tissue.

The mesh is desirably self-opening upon emplacement over the myopectineal orifice. The mechanism for self-opening for the prosthesis must be reliable and should further provide suitable rigidity to the prosthesis in an open configuration, without unduly interfering with the anatomical members in the vicinity of the myopectineal orifice. Specifically, while the prosthesis should provide support to each side of the myopectineal orifice, the prosthesis should not interfere with, and risk closing of, the vas deferens. Additionally, the prosthesis should pose no risk of puncturing the peritoneum so as to induce infection.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a device for creating an operating space in registry with the herniated region of a patient.

It is another object of the invention to provide a device for delivering a surgical prosthetic mesh to operating space in registry with a herniated region of a patient.

It is yet another object of the present invention to provide a device for performing herniorrhaphy having a relatively small diameter so as to minimize the need for general anesthesia.

It is still yet another object of the invention to provide a mechanism for separating adjacent tissue layers within a patient so as to provide an operating space.

It is even still another object of the present invention to provide a mechanism for separating adjacent tissue layers within a patient that may delivered through a small diameter cannula.

It is yet even another object of the present invention to provide a mechanism which may be delivered through a small diameter cannula that will both separate adjacent tissue layers and deliver a prosthetic mesh to the operating space being created.

In the efficient attainment of these and other objects, the present invention provides an instrument for creating an operating space in a body in the form of an elongate blunt-nose cannula having an elongate side wall defining an access aperture, an interior lumen, and an elongate aperture. The cannula is deliverable along a guidewire between a first and second tissue layer in a body. The instrument also includes a retractable outer protective sheath, a fluid delivery lumen communicating with a fluid source, and a hollow expandable tissue separating balloon including a first major surface and a second major surface. The first major surface is peripherally contiguous with the second major surface and together the first and second major surfaces define a fluid-tight balloon cavity therebetween. The balloon cavity communicates with the fluid delivery lumen and is expandable through the elongate aperture of the cannula body from a first contracted configuration confined within the cannula body to a second expanded configuration extending through the elongate window. Expansion of the balloon thereby forces apart the adjacent first and second tissue layers so as to form the operating cavity.

The delivery cannula of the present invention is less than about 10 millimeters although diameters of between about 5 millimeters and 2 millimeters is desirable. Therefore the tissue separating balloons of the present invention are designed to have shapes which may be rolled, folded, or collapsed within a small diameter lumen. For example, several of the balloons of the present invention provide major surfaces with opposed tapering edges. The major surfaces of these balloons may be pleated, or alternately folded upon themselves, so as to effectively telescope outwardly from the stored configuration upon balloon inflation. The tapering edges minimize bunching up of the balloon material and thereby minimize the required mean diameter of the delivery cannula.

The cannula and balloon of the present invention are contemplated as providing for expansion of the balloon towards one side of the cannula. The cannula and balloon of the present invention are also contemplated as providing for expansion of the balloon towards two opposing sides of the cannula so as to centrally locate the guidewire in registry with the operating site being treated. Additionally, the balloon of the present invention may be formed to expand symmetrically about the cannula or in a longitudinally reversed symmetry so as to position the guidewire in registry with a diagonal axis of the operating space being treated.

Alternatively, the present invention provides a boundary balloon in that the balloon takes the form of a tubular wall having a substantially rectangular frame shape. In its fully inflated state the balloon is positioned only at the periphery of the created operating space. As it is not necessary to maintain the tissue layers apart once separated, a frame balloon provides for a maximum amount of space to be created for a given amount of balloon material. As less material is required to create an operating space, the diameter of the delivery cannula may be further reduced.

It is further contemplated that each of the balloons of the present invention may carry a porous surgical mesh so that upon expansion of the balloon the mesh will be unfurled over the operating site. The mesh may be detachable from the balloon so that the balloon may be withdrawn from the operating space once the mesh is emplaced. It is also contemplated that the balloon of the present invention may itself be detached from the fluid delivery lumen of the cannula so that the balloon may be left within with the mesh in registry with the operating space. Such a detachable balloon would be desirably formed from a bioabsorbable material.

In order to further minimize the required diameter of the cannula, the present invention also contemplates a detachable balloon having a major surface formed from a plugged porous surgical mesh. That is, the pores of the surgical mesh are plugged or filled so as to maintain the fluid integrity of the balloon during expansion by internal fluid pressure. However, the material used to fill the pores of the mesh will also be bioabsorbable so that as the filler material is absorbed by the body, the pores will be exposed so as to permit new tissue ingrowth therethrough. The remainder of the balloon is also formed from a bioabsorbable material. This balloon obviates the need for providing a major surface of the balloon simply to support a prosthetic mesh thereon and thereby decreases the required stored volume of the balloon and diameter of the delivery cannula.

The present invention also contemplates a device for creating an operating cavity in a mammal between two adjoining layers of tissue adjacent to an operating site on one of the tissue layers. The device includes an elongate hollow cannula defining an elongate interior lumen, an access port communicating with the interior lumen and accessible outside the body of a patient, and an elongate aperture also communicating with the interior lumen and accessible to the deployment area. The device includes a blunt nose for introducing the device into the body, and a guidewire-deliverable dissecting member which is deliverable within the interior lumen of the cannula to a deployment area adjacent to the operating site.

In one embodiment of the present invention, the cannula supports a dissecting member including an elongate dissecting tip transversely extendable from the elongate aperture of the dissecting member. The dissecting member further includes actuator means for retractably extending the dissecting tip from the dissecting member to separate layers of tissue adjacent the operating area to form the operating cavity. The dissecting tip is a substantially rigid member which will exhibit a minimum of deflection as it is extended between to the adjacent tissue layers so as to separate same.

The actuator means is desirably a pair of elongate push rods which extend and retract normally to the dissecting member and which may bend to negotiate a ninety degree turn so as to extend longitudinally through the cannula. The cannula desirably provides exclusive passageways for accommodating each push rod. The passageways are desirably conformally shaped to the outside surfaces of the push rods, which are desirably both rectangular. In order to minimize the buckling of the push rods as the dissecting tip is extended, the cannula passageways desirably impart a twist to the push rods so that deflection of the push rods will be directed against the adjacent tissue layers and not simply therebetween. A surgeon may apply light pressure from the outside of the patient to counteract the buckling of the push rods. Once the dissecting tip has been pushed to its maximum limit, the push rods may be retracted back through the cannula. If desired, especially where it is beneficial to centrally locate the guidewire within the operating space, the operator may rotate the cannula about the guidewire and extend the dissecting tip in the transversely-opposite direction so as to provide a larger operating cavity.

The present invention also contemplates providing a flexible wire within the cannula that has one end anchored to the blunt nose and the opposed free end extending through the lumen exterior of the patient. This embodiment further provides an elongate cannula window opening in one transverse direction towards the non-separated tissue layers. The flexible wire may be extended towards the blunt nose so as to buckle the wire outwardly through the cannula window so as to be forced between and to separate the adjacent tissue layers in order to form the operating cavity. The flexible wire may be formed having a cross-sectional shape which favors buckling towards the cannula window. The flexible wire may also have various projections on the surface thereof which facilitate tissue separation. Additionally, the cannula may provide a longitudinally centrally located protrusion formed on the cannula wall in facing opposition to the window and adjacent the flexible wire so as to instigate buckling of the wire towards the window. After retracting the flexible wire back into through the window, the operator may rotate the cannula about the guidewire until the window faces in the opposite transverse direction as before so as to provide an enlarged operating cavity with the guidewire centrally located in registry therewith. An alternate embodiment of this device provides a second elongate window communicating to the opposite direction as the first window and a second flexible wire similarly anchored to the blunt nose for extension through the second window so as to simultaneously form the enlarged operating space to either side of the guidewire.

The present invention further contemplates providing a tissue dissecting device within the cannula which is formed from a shape memory material and which has been deformed to be deliverable within the cannula to a location between two adjacent tissue layers in the body. The shape memory material is desirably activated by body temperature to assume a configuration where a tissue separating blade extends out through the cannula window and thereby separate the adjacent tissue layers. The extended blade is desirably longitudinally movable along the length of the window to create the desired operating space. The blade is desirably connected to an actuating rod extending through the lumen of the cannula outside the patient. An alternate embodiment of this device provides a second tissue separating blade formed from a shape memory material to extend in the opposite transverse direction so that the guidewire will be centrally located within the resulting operating cavity.

An even further embodiment of the present invention provides a pair of oppositely-extendable elongate blades having one end pivotally connected to a pivot pin carried at one end of an elongate support wire adjacent a blade stop surface. The opposite ends of the blades are transversely separated by a deployment wedge which is supported at the end of an elongate actuation wire. The deployment wedge includes a planar face in facing opposition to the blade stop surface. The actuation wire is extendable and retractable along the support wire. Retraction of the actuation wire retracts the deployment wedge which forces the blades to pivot outwardly from the cannula to separate the adjacent tissue layers. The blades transversely extend from the cannula when the planar face of the deployment wedge pins the blades against the blade stop surface. The operator may then axially extend both the actuation wire and the support wire so as to extend the tissue separating blades along the length of the cannula window and thereby form the operating cavity.

The present invention even further provides a device for delivering a surgical prosthetic mesh to a previously-formed operating space. The mesh delivery device includes an elongate cannula body having an elongate cannula cylindrical wall of a first outside diameter supporting an elongate cylindrical guidewire conduit having a second smaller outside diameter and an interior passageway for accommodating a guidewire. The distal end of the guidewire conduit supports a blunt nose including a cylindrical rim having the same diameter as the cylindrical cannula wall. The device defines a cylindrical cannula window, and a cylindrical mesh delivery area about the guidewire conduit, between the cannula cylindrical wall and the blunt nose. An elongate retractable sheath extends along the outside of the cylindrical cannula wall to the surface of the rim of the blunt nose. A prosthetic mesh is deployably wrapped about the guidewire conduit. The mesh may be wrapped by placing one edge of the mesh along the guidewire conduit and then furling the mesh about thereabout. Once the cannula is positioned within the operating cavity, the sheath is retracted to expose the prosthetic mesh. The free edge of the mesh may be grasped and transversely pulled to deploy the mesh within the operating space.

Alternatively, the mesh may be longitudinally folded so that the opposed edges of the mesh are brought towards each other. The crease is then place along the guidewire conduit. Furling the mesh about the guidewire conduit provides the opposed edges to either side of the guidewire conduit. The opposed edges may be simultaneously pulled in opposite directions to deploy the mesh within the operating space. This alternative delivery configuration for the mesh is advantageously employed when the guidewire is centrally located within the operating cavity.

The present invention also provides methods for employing the devices of the present invention.

The present invention will be more readily appreciated in a reading of the "Detailed Description of the Preferred Embodiments" with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the insertion of a guidewire in registry with a herniated region according to the present invention.

FIG. 2 depicts a guidewire positioned in registry with a herniated region.

FIG. 3 is an elevational schematic of a guidewire inserted in registry with a herniated region within a patient.

FIG. 4 depicts a cannula for delivering a tissue separating device of the present invention.

FIG. 5 is a partial cut away view of the cannula of FIG. 4.

FIG. 6 shows a tissue separating balloon of the present invention.

FIG. 7 depicts a cannula for delivering the tissue separating balloon of FIG. 6.

FIG. 8 is a partial cutaway view of the cannula of FIG. 7.

FIG. 9 is a cross-sectional view of the cannula in FIG. 7 showing one delivery configuration for the tissue separating balloon.

FIG. 10 is cross-section of the cannula of FIG. 7 depicting an alternate delivery configuration for the tissue separating balloon carried therein.

FIGS. 11, 12 and 13 depict a second embodiment for a tissue separating balloon of the present invention.

FIGS. 14 and 15 depict alternate delivery configurations for the tissue separating balloon of FIGS. 11-13.

FIG. 16 is a schematic representation of the tissue separating balloon of FIGS. 11-13 when delivered as shown in FIG. 15.

FIG. 17 depicts yet another tissue separating balloon of the present invention.

FIG. 18 is a cross-sectional view of the tissue separating balloon of FIG. 17 as configured within a delivery cannula of the present invention.

FIG. 19 is a top view of one wing of the tissue separating balloon of FIG. 17 being folded into a pleated delivery configuration.

FIGS. 20 and 21 depict still another tissue separating balloon of the present invention.

FIG. 22 depicts the folding of the tissue separating balloon of FIGS. 20 and 21 for delivery within a cannula of the present invention.

FIG. 23 depicts the tissue separating balloon of FIGS. 20 and 21 within a delivery cannula of the present invention.

FIGS. 24 and 25 depict even still another tissue separating balloon of the present invention.

FIG. 26 provides an elevational view of one wing of the tissue separating balloon of FIGS. 24 and 25 in the inflated configuration.

FIG. 27 is a cross-sectional view of the tissue separating balloon of FIGS. 24 and 25 folded in a serpentine within a delivery cannula.

FIG. 28 is a cross-sectional view of a tissue separating balloon of FIGS. 24 and 25 in a rolled configuration within a delivery cannula of the present invention.

FIG. 29 is a cross-sectional view of a tissue separating balloon of FIGS. 24 and 25 in a pleated configuration within a delivery cannula of the present invention.

FIGS. 30-38 depict an alternate embodiment of a tissue separating device of the present invention.

FIGS. 39-43 depict yet another alternate embodiment of a tissue separating device of the present invention.

FIGS. 44 and 45 depict an alternate embodiment of the tissue separating device of FIGS. 39-43 employing two tissue separating members.

FIGS. 46 and 47 depict a tissue separating device of the present invention employing a tissue separating blade formed from a shape memory material.

FIGS. 48 and 49 depict an embodiment of the tissue separating device of FIGS. 46 and 47 providing two tissue separating blades formed from a shape memory material.

FIGS. 50-54 depict a further tissue separating device of the present invention employing an extendable wire tissue-separating means.

FIG. 55 depicts a tissue separating balloon of the present invention having a detachable prosthesis attached to one major surface thereof.

FIG. 55a depicts a separable connector design for the fluid conduit of the balloon of FIG. 55.

FIG. 56 depicts the tissue separating balloon of FIG. 55 deploying a prosthesis within an operating space created thereby.

FIG. 57 depicts a tissue separating balloon of the present invention having one major surface formed from a plugged porous material which may be separated and emplaced within an operating space created thereby.

FIG. 58 depicts the tissue separating device of FIG. 57 being left in place within the operating space formed thereby.

FIGS. 59-65 depict a prosthesis delivery device of the present invention and the use thereof.

FIG. 66 depicts a thin mesh being expelled from a small diameter cannula in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to devices and methods for performing hernia repair. The present invention provides for repairing hernias using needle herniorrhaphy techniques which may be performed using only a local anesthesia on an out-patient basis.

Needle herniorrhaphy is a laparoscopic-like method of repairing a hernia utilizing a trocar on the order of about five to ten millimeters in diameter although it is contemplated that a trocar of about two millimeters in diameter may also be utilized. Referring to FIGS. 1-3, a method employing the devices of the present invention inserts an elongatehollow trocar 10 through theabdominal wall 12 of a patient from one side of the herniatedregion 14, passes thetrocar 10 over theperitoneum 16 above the herniatedregion 14, and out through theabdominal wall 12 of the patient opposite the herniatedregion 14 from where thetrocar 10 was inserted. Afirst end 17 of aguidewire 18 is inserted through afirst end 20 of thetrocar 10 and out thesecond end 22 of thetrocar 20 so as to extend completely through thetrocar 10.Trocar 10 is then pulled overfirst end 17 ofguidewire 18 until out of the patient and then removed from theguidewire 18 altogether. Anelongate cannula 24 for providing atissue dissection device 26 of the present invention is then threaded over one end ofguidewire 18 and inserted thoughabdominal wall 12 until positioned adjacent the peritoneum 16 over the herniatedregion 14. Thetissue dissection device 26 is operated to separate theabdominal wall 12 from the peritoneum 16 about the herniatedregion 14 to create an operatingspace 28 in registry therewith. Operatingspace 28 is desirably formed in registry with themyopectineal orifice 32 and extends approximately 2 to 3 centimeters beyond the perimeter thereof. As will be discussed hereinbelow, after operatingspace 28 has been created, thehernia sac 25 may be ligated and aprosthetic mesh 30 may be deployed over the herniatedregion 14 of the peritoneum 16 so as to induce tissue growth through themesh 30 and to effect repair of the hernia.

The present invention provides several devices and methods for performing the steps of separating the abdominal wall from the peritoneum and for deploying a mesh over the herniated region of the peritoneum. The devices and methods for each step may be combined to form a composite device or devices for performing the herniorrhaphy. These devices and methods will be described in greater detail hereinbelow.

1. Guidewire Emplacement

With reference to FIG. 1, a method for treating an inguinal hernia includes running aguidewire 18 above themyopectineal orifice 32.Guidewire 18 may be positioned by pinching theabdominal wall 12 adjacent themyopectineal orifice 32 to isolate an exploitable junction 33 therebetween theperitoneum 16 and theabdominal wall 12. Apenetration end 22 of an elongatehollow trocar 10 is then inserted through theabdominal wall 12, forminginsertion puncture 36, until between the peritoneum 16 and theabdominal wall 12.Penetration end 22 is pushed between the peritoneum 16 and theabdominal wall 12 so as to pass over the region of themyopectineal orifice 32 where it then punctures throughabdominal wall 12, formingexit puncture 38, to exit the body of the patient.Penetration end 22 may be formed having a relatively blunt shape so as to minimize the risk of scratching or puncturing the peritoneum 16 as it formsgap 34. Such shapes for blunt needles are well known in the art.Trocar 10 is formed of a suitable surgical material and desirably is formed having an outer diameter between 2 and 10 millimeters.

Withtrocar 10 now percutaneously transiting the body adjacent the herniatedregion 14,first end 17 ofguidewire 18 is inserted throughfirst end 20 oftrocar 10 and therethrough and out of penetration end oftrocar 22. Holdingguidewire 18 stationary,trocar 10 is fully pulled throughgap 25 overguidewire 18 in the direction of arrow A until clear offirst end 17. Now guidewire 18 percutaneously transits the body over the herniatedregion 14 betweeninsertion puncture 36 andexit puncture 38.Guidewire 18 is formed of a suitable surgical material as is known in the surgical arts and is desirably selected so as to minimize the risk of scratching or cutting the peritoneum.

2. Guidewire-Deliverable Cannula

Withguidewire 18 now positioned proximal to herniatedregion 14, anelongate cannula 24, shown in FIGS. 4-5, may be delivered alongguidewire 18 throughinsertion puncture 36 to a position withingap 34.Cannula 24 includes ablunt tip 40 at afirst end 42, acannula wall 48 at asecond end 46, and anelongate guidewire conduit 27 extending therebetween.Cannula 24 is desirably formed of stainless steel when formed having a relatively small outside diameter. It is also contemplated thatcannula 24 may be desirably formed of a suitable surgical plastic material when formed having a relatively larger outside diameter.

Cannula wall 48 defines anaccess aperture 44 atsecond end 46 and aninterior passageway 50 extending towardsblunt tip 40. The exterior ofcannula 24 further includes an elongate hollowretractable sheath 64 extending fromblunt tip 40 towards access aperture 44 a sufficient length so as to protrude frominsertion aperture 36 whencannula 24 is positioned withingap 34.Sheath 64 covers adelivery cavity 76 extending from adistal rim 49 ofcannula wall 49 to blunttip 40.Cannula 24 further defines anelongate cannula window 52 extending betweenblunt tip 40 anddistal rim 49 ofcannula wall 48 and providing access todelivery cavity 76.Sheath 64 provides protective cover overcannula window 52 anddelivery cavity 76 for delivery withingap 34.

Blunt tip 40 is further described as including anoblong nose body 62 having a leadingsurface 63 tapering from a transversely-oriented sheath-accommodatingrim 65 towards anopen tip 70.Nose body 62 also includes acylindrical annulus 67 spaced acrossrim 65 fromlead surface 63.Annulus 67 releasably adheres to the distal end 64a ofretractable sheath 64. Once positioned withingap 34, the protruding end ofsheath 64 may be pulled in the direction of arrow B so as to retract fromannulus 67 and thereby exposedelivery cavity 76 togap 34 betweenabdominal wall 12 andperitoneum 16.Blunt tip 40 andguidewire conduit 27 define aguidewire passageway 68 for accommodatingguidewire 18 therethrough.Guidewire passageway 68 desirably communicates through the interior ofnose body 62 adjacent toannulus 67. It is further contemplated thatguidewire passageway 68 may traverse withinnose body 62 to exit through centrally locatedtip 70.Guidewire passageway 68 allows for protected relative displacement betweenguidewire 18,cannula wall 48, and anytissue separating devices 26 passing throughinterior passageway 50 todelivery cavity 76.

Cannula 24 is therefore deliverable overguidewire 18 so as to positioncannula window 52 withingap 34 proximal to the herniatedregion 14.Cannula 24 accommodatestissue dissection devices 26 of the present invention extending fromdelivery cavity 76 throughcannula window 52 for separating theabdominal wall 12 from the peritoneum 16 as will be hereinbelow described. Eachtissue dissection device 26 may form operatingspace 28 in registry with themyopectineal orifice 32.

3. Tissue Dissection Devices

A. Balloon Dissection Devices

The present invention provides alternate embodiments for atissue dissection device 26 which may be delivered alongguidewire 18 to form a bloodless operating cavity. With reference to FIGS. 6-29, atissue dissection device 26 of the present invention may take the form of aballoon dissection device 60. Each variant ofballoon dissection device 60 of the present invention incorporatescannula 24 and further provides an inflatable tissue-separatingballoon 74, as generally represented in FIGS. 6 and 7. Tissue-separatingballoon 74 is deliverable withindelivery cavity 76 in a collapsed configuration and is expandable to an expanded configuration throughcannula window 52. Expansion of tissue-separatingballoon 74 extends afirst wing 74a in a direction diametrically opposite to the direction in which asecond wing 74b extends.Wings 74a and 74b extend along a path between the adjacent tissue planes 12 and 16 so as to separatelayers 12 and 16 and thereby form operatingspace 28.

Tissue-separatingballoon 74 is desirably formed of a substantially inelastic and surgically suitable material and includes a firstmajor surface 78 peripherally contiguous with an opposing secondmajor surface 80.Balloon 74 further includes a first proximaltransverse face 79 and a second distaltransverse face 81. The transverse extents ofmajor surfaces 78 and 80 may be joined at afirst seam 82a and asecond seam 82b, respectively, as shown in FIG. 6, or across a perimetrical face 84, as shown in FIG. 11.Balloon 74 defines aballoon interior 86 in fluid communication with afluid conduit 72.Fluid conduit 72 extends throughpassageway 50 in fluid communication between a fluid source, not shown, andballoon interior 86. Bothballoon 74 andfluid conduit 72 are formed to provide fluid tight communication with the fluid source.

Balloon 74 may be provided in the collapsed configuration for delivery whereby eachwing 74a and 74b is alternatingly folded aboutmajor surfaces 78 and 80 in a serpentine fashion as shown in FIG. 9. Alternatively,balloon 74 may be provided in the collapsed configuration for delivery by rollingballoon 74 fromdistal end 81. The fully rolled balloon may then be compressed to effectively form opposingcreases 78' and 80' insurfaces 78 and 80 so as to conform todelivery cavity 76 as shown in FIG. 10.

The operation of the tissue-separating balloon is substantially the same regardless of the form finally selected. The present invention contemplates deliveringballoon 74, in a collapsed configuration withindelivery cavity 76 ofdevice 60. Oncedevice 60 is properly positioned withingap 34,sheath 64 will be pulled in the direction of arrow B away fromnose body 62 to fully expose collapsedballoon 74. The fluid source will supply a fluid, desirably a saline solution, throughfluid conduit 72 intoballoon interior 86. The internal pressure provided by the fluid will causeballoon 74 to expand outwardly fromdevice 60 to assume an expanded configuration. Expansion may further be aided by providing a pulsating excitement to the fluid, as is known in the art. Operatingspace 28 will be fully realized through either the expansion of, or the final expanded configuration assumed by,balloon 74. Onceballoon 74 is fully expanded, the direction of flow from the fluid source may be reversed so as to remove the fluid fromballoon interior 86 and thereby deflateballoon 74. Once deflated,balloon 74 may be withdrawn from operatingspace 28 through either ofpunctures 36 or 38. The present invention also contemplates disconnectingballoon 74 fromfluid conduit 72 so as to leaveballoon 74 in place overoperating space 28 as will be described in further detail hereinbelow.

Referring now to FIG. 6a, it is contemplated that tissue dissection may be further aided by further providingballoon 74 with arigid dissection tip 90 along each ofseams 82a and 82b.Dissection tip 90 desirably included a leading edge 92 which is pushed between adjacent tissue layers 12 and 16 asballoon 74 is inflated.Dissection tip 90 may be formed of a suitable surgical plastic material.Dissection tip 90 may alternatively be formed by a metallic material which may be excited by an external stimulus, such radio frequency energy, so as to vibrate and further induce separation of tissue layers 12 and 16. Suitable metallic materials are well known in the art.

Other variants ofballoon 74 contemplated by the present invention will now be discussed. Similar numbering of similar components which perform similar functions is employed when possible. Each variant ofballoon 74 may be delivered alongguidewire 18 to a position withingap 34 so as to be expandable between adjacent tissue layers 12 and 16 andform operating space 28. Each balloon is inflatable by a fluid as described hereinabove. Tissue dissection by each balloon may be further aided by providing a pulsating excitation to the fluid as the balloon is expanded. Additionally, while not shown, the present invention contemplates that each balloon variant may further include adissection tip 90 as described hereinabove.

Tissue separating balloon 74 may take the form of a divergingfrustrum balloon 174 as shown in FIGS. 11-16.Balloon 174 is said to be diverging as each ofmajor surface 178, 179, 180, and 181 are seen to be diverging from a smallercentral portion 175 which is longitudinally aligned withfluid conduit 172.Balloon 174 includes a pair of opposeddistal faces 184a and 184b which perform the majority of the tissue-separating function.Balloon 174 provides a desirable shape for collapsingballoon 174 into a contracted configuration withinballoon interior 186 for delivery. As each ofsurfaces 178, 179, 180, and 181 taper outwardly from thecentral portion 175 whenballoon 174 is in the expanded configuration,balloon 174 may be collapsed withininterior 186 so as to minimize its profile in the collapsed configuration. As shown in FIGS. 15 and 16, the collapsed configuration ofballoon 174 is achieved by similarly pleatingsurfaces 178, 179, 180, and 181 so thatdistal faces 184a and 184b are exposed togap 34 when sheath 164 is retracted.Interior surface 184a ofdistal face 181 may therefore be provided in unobstructed fluid communication across frominlet port 177 to thereby ensure reliable balloon expansion.

Distal face 184 is desirably formed having a longitudinal length equal to one dimension of the desiredoperating space 28 to be formed as distal face 184 extends transversely fromcentral portion 175 during inflation. Asballoon 174 expands to its fully inflated configuration, distal face 184 will have pushed open at least a portion of operatingspace 28 even thoughballoon 174 will only partially thereoccupy. Alternatively,balloon 174 may providedistal faces 184a and 184b transversely spaced a distance equal to the length of the other major dimension of the desiredoperating space 28 to be formed so that inflation ofballoon 174 will separate aoperating space 28 of the desired dimensions.

With reference to FIGS. 17-19, the present invention further contemplates providing a tissue-separatingballoon 274 taking the form of a converging frustrum as each ofmajor surfaces 278, 279, 280, and 281 taper from a largercentral portion 275 to smaller transversely-extending distal ends.Balloon 274 includes a pair ofopposed wings 274a and 274b and a pair of opposeddistal edges 282a and 282b which perform the majority of the tissue-separating function.Balloon 274 provides a desirable shape for collapsingballoon 274 into a contracted configuration withinballoon interior 286 for delivery as shown in FIGS. 18-19. As each ofsurfaces 278, 279, 280, and 281 taper outwardly from thecentral portion 275 whenballoon 274 is in the expanded configuration,balloon 274 may be collapsed withininterior 286 so as to minimize its profile in the collapsed configuration. As shown in FIGS. 18 and 19, the collapsed configuration ofballoon 274 is achieved by similarly pleatingsurfaces 278, 279, 280, and 281 so thatdistal edges 282a and 282b are exposed togap 34 when sheath 264 is retracted. Interior edge 286a ofdistal edge 282 may therefore be provided in unobstructed fluid communication across frominlet port 277 to thereby ensure reliable balloon expansion.

Distal edge 282 is desirably formed having a longitudinal length equal to one dimension of the desiredoperating space 28 to be formed asdistal edge 282 extends transversely fromcentral portion 275 during inflation. Asballoon 274 expands to its fully inflated configuration,distal edges 282a and 282b will have pushed open at least a portion of operatingspace 28. Alternatively,balloon 274 may further providedistal edges 282a and 282b transversely spaced a distance equal to the length of the other major dimension of the desiredoperating space 28 to be formed so that inflation ofballoon 274 will separate aoperating space 28 of the desired dimensions.

Referring now to FIGS. 20-23, the present invention further contemplates a tissue-separatingballoon 374 having an elongate hollow tubular wall having a substantially rectangular frame shape so as to define the outer perimeter of operatingspace 28 in the expanded position. Tissue-separatingballoon 374 is advantageous in that it requires less material than a planar structure such as those shown previously and may therefore require a smaller delivery cavity defined by a smaller diameter delivery device. With reference to FIGS. 20-21,tissue separating balloon 374 is defined in an expanded position by two pair oftransverse balloon segments 300, 302 and 301, 303 extending in fluid communication from fluid conduit 372 to opposite ends of a pair of elongate longitudinally-orientedtubular balloon segments 304 and 305, respectively. In the expanded position, tissue-separatingballoon 374 desirably defines the perimeter of the operatingspace 28.

Referring now to FIGS. 22-23,balloon 374 may be provided in a collapsed configuration by foldingballoon segments 300, 301, 302, and 303 at their respective midpoints 300a, 301a, 302a, and 303a so as to be deliverable within delivery cavity 276 of balloon dissection device 260. Whileballoon 374 is shown to have a rectangular perimetrical shape, other configurations forballoon 374 may be provided depending on the particular shape of the operating space desired to be created without departing from the teachings of the present invention.

A still further configuration for the balloon of the present invention is depicted in FIGS. 24 and 25, wherein balloon 474 is provided as part of balloon dissection device 460 and as having two asymmetrically extendinginflatable balloon wings 474a and 474b. The present invention contemplates delivering balloon dissection device 460 along the diagonal of arectangular operating space 28 to be positioned in registry with an operating site such as themyopectineal orifice 32. It can be appreciated from FIG. 24 thatballoon wings 474a and 474b are similarly formed but longitudinally reversed with respect to dissection device 460.Balloon 474a will therefore be described in detail as also representative of the construction and operation ofballoon 474b.

Balloon 474a includes opposedmajor surfaces 478 and 480 being peripherally contiguous acrosssidewalls 479 and 481.Surfaces 478 and 480 andsidewalls 479 and 481 defineballoon edges 478a, 478b, 480a, and 480b extending fromcentral portion 475 of balloon 474 and converging upon adistal apex 485 oppositecentral portion 475.Balloon 474a defines aballoon interior 486 in fluid communication withfluid conduit 472. As shown in FIG. 27,balloon 474a may be provided in the collapsed configuration for delivery wherebyballoon 474a is alternatingly folded aboutmajor surfaces 478 and 480 in a serpentine fashion. Alternatively, as shown in FIG. 28,balloon 474a may be provided in the collapsed configuration for delivery by rollingballoon 474a fromdistal apex 485. The fully rolled balloon may then be compressed to effectively form opposing creases 478' and 480' insurfaces 478 and 480 so as to conform todelivery cavity 476.

As shown in FIG. 29, the collapsed configuration ofballoon 474a may also be achieved by similarly pleatingmajor surfaces 478 and 480 so thatdistal apex 485 facesgap 34 whensheath 464 is retracted for delivery. Interior apex 485a ofdistal apex 485 may therefore be provided in unobstructed fluid communication across frominlet port 477 to thereby ensure reliable balloon expansion. Likeballoon 274,balloon 474a may be delivered in this pleated manner so as to minimize its profile in the collapsed configuration. It is desirable forballoon 474a to be sized to form about one half of operatingspace 28 so that the longitudinally reversedballoons 474a and 474b together provide the desiredoperating space 28 in registry with the operating site.

B. Mechanical Blade Dissection Devices

The present invention also contemplates thattissue dissection device 26 may take the form of a mechanical device which may be delivered togap 34 alongguidewire 18 and operate to form a bloodless operating cavity. Referring now to FIGS. 30-38, the present invention provides a transversely extendable and retractable elongatetissue dissection device 600.Device 600 incorporatescannula 24 and further provides an elongatetissue dissection blade 602 having anarcuate surface 604 coextensive with a portion ofcannula window 52.Device 600 desirably is deliverable alongguidewire 18 intogap 34 at whichpoint sheath 64 may be retracted from aposition enclosing blade 602 to a position wherebyblade 602 may be extended intogap 34 between adjacent tissue layers 12 and 16 so as to form operatingspace 28 in registry with themyopectineal orifice 32 of a patient.Surface 604 is desirably a blunt arcuate surface so as to minimize the risk ofblade 602 burrowing through a tissue layer as it is extended fromdevice 600.

With reference to FIGS. 31-33,blade 602 includes afirst end 606, asecond end 608 and an elongateoblong blade body 610 extending therebetween.Oblong blade body 610 includesarcuate surface 604 along one major surface thereof and an opposing arcuatemajor surface 612.Blade 602 supports a pair of orthogonally-orientedelongate pusher rods 614 and 616adjacent ends 606 and 608 respectively.Pusher rods 614 and 616 extend from fixedends 614a and 616a to free ends 614b and 616b respectively.Blade 602, includingpusher rods 614 and 616, is desirably formed of a suitable flexible plastic material such as polypropylene.

As shown in FIG. 32,pusher rods 614 and 616 have substantially rectangular cross-sections defined between a pair ofmajor surfaces 618a, 618b and 620a, 620b, all of which are acutely oriented with respect to the longitudinal axis ofblade 602. As shown in FIG. 30, each ofpusher rods 614 and 616 are acutely oriented so as to be receivable in a pair ofelongate passageways 622 and 624 formed withindelivery cavity 76. Eachpassageway 622 and 624 extends from afirst end 622a and 624a defined ataccess aperture 44 to asecond end 622b and 624b opening in fluid communication withcannula window 52, respectively.Passageways 622 and 624 have dimension closely conforming to the cross-sectional dimensions ofpusher rods 614 and 616 so as to minimize buckling deflection of the pusher rods about major surfaces while therein.

With additional reference to FIGS. 34 and 37, each ofpassageways 622 and 624 are further shaped so as to orthogonally turn and longitudinallytwist pusher rods 614 and 616, respectively, towards parallel alignment as each extends fromaccess aperture 44. Asblade 602 is positioned withincannula window 52 for delivery,free end 614b and 616b extend out fromaccess aperture 44 for grasping by a surgeon. As shown in FIG. 37, longitudinal movement of free ends 618 and 620 in the directions of arrows C and D causes the transverse movement ofblade 602 in the directions of arrows E and F, respectively. The acute alignment ofpusher rods 614 and 616 at fixed ends 614a and 616a ensures thatmajor surfaces 618a, 618b, and 620a, 620b are turned towards each of the adjacent tissue layers 12 and 16. With this orientation, tissue layers 12 and 16 may help pusherrods 614 and 616 resist buckling during extension fromcannula window 52. Should the buckling of one pusher rod become too severe, the surgeon can simply retract both pusher rods in the direction of arrow D until the slack in the buckling pusher rod is taken up. The surgeon may then apply light pressure with one hand on the patient's abdomen to further help restrain longitudinal buckling of the pusher rod.

Device 600 is desirably provided along a centerline bisecting the myopectineal orifice. Extension ofblade 602 from the centerline may therefore open approximately one half of operatingspace 28 at whichpoint blade 602 would be retracted back withincannula window 52. The surgeon would then rotatedevice 180 degrees about its longitudinal axis so thatblade 602 faces in an opposite transverse direction so as be positioned to separate tissue layers 12 and 16 and fully form operatingspace 28. Once the operating space is fully formed,blade 602 is retracted back withincannula window 52 anddevice 600 may be removed therefrom.

Referring now to FIGS. 39-43, the present invention provides an extendable tissue-separatingdevice 630 deliverable alongguidewire 18. Tissue-separatingdevice 630 conforms to the general design ofcannula 24 by providing ablunt nose 632 at one end of anelongate cannula wall 634 having aguidewire conduit 636 extending therealong and throughblunt nose 632.Tissue separating device 630 includes aproximal housing 638accommodating guidewire conduit 636 and a dissection member passageway 640.Cannula wall 634 defines both acannula interior 641 and anelongate window 642 extending fromhousing 638 towardsblunt nose 632. During use,proximal housing 638 desirably extends fromgap 34 through theabdominal wall 12 and is exposed to, and accessible by, a surgeon. Tissue-separatingdevice 630 accommodatesretractable sheath 64, shown in phantom lines, so as to provide easier insertion thereof intogap 34.Sheath 64 may be retracted fromblunt nose 632 overhousing 638 so as to expose an elongate tissue-separatingmember 644. Tissue-separatingdevice 630 may be formed having a very small diameter in that it need only accommodateguidewire 18 and a similarly-sized tissue-separatingmember 644. While it is contemplated thattissue separating device 630 has an external diameter of about 10 millimeters, it is also contemplated that the diameter may be about 5 millimeters and preferably about 2 millimeters.

Tissue-separatingmember 644 extends from ananchored end 644a atblunt nose 632 through dissection member passageway 640 ofhousing 638 to afree end 644b and includes abody portion 644c extending therebetween.Anchored end 644a may be conventionally fixed within a receiving cavity 646 defined by a base surface 648 ofblunt nose 632 or otherwise positioned thereadjacent so as to be flexible thereabout.Body portion 644c is extendable and retractable throughwindow 642 by actuation offree end 644b in the direction of arrows G and H, respectively. Tissue-separating member is desirably formed of a flexible yet resilient material such as stainless steel or a suitable surgical plastic such thatbody portion 644c buckles and extends throughcannula window 642. Asfree end 644b is moved further in the direction of arrow G,body portion 644c will buckle further and extend in the direction of arrow I so as to pass between and separate the adjacent tissue layers 12 and 16 and thereby define operatingspace 28 of the desired dimensions.

It is contemplated that tissueseparation using device 630 may require a reciprocating motion offree end 644a in the directions of arrows G and H so as to deflectbody portion 644c in the directions of arrows I and J such that with ever increasing stroke lengths in the direction of arrow G will cause a larger deflection in the direction of arrow I so as to thereby increase the size of the opened operatingspace 28. It is further contemplated that an external excitation force such as a radio frequency vibration may be applied to tissue-separatingmember 644 to further assist in separating adjacent tissue layers 12 and 16. As withdevice 600, a surgeon may apply light pressure with one hand on the patient's abdomen to help maintain the buckling of tissue-separatingmember 644 within the plane between the adjacent tissue layers 12 and 16.

The dimensions of the operatingspace 28 provided bytissue separating device 630 is chiefly a function of the longitudinal length ofcannula window 642 and the length of tissue-separatingmember 644 fed throughproximal housing 638 by a surgeon. The present invention contemplates that the length ofcannula window 642 may be fixed for a givendevice 630. Furthermore, the present invention contemplates that the length ofcannula window 642 may be made selectable by providing an elongate rigidhollow duct 654 including afirst end 655 defining anopening 656.Duct 654 is formed to slide over the outside ofproximal housing 638 andcannula 24 so as to positionfirst end 655 over a portion ofcannula window 642 to thereby reduce the opening through which tissue-separatingmember 644 may extend. It is also contemplated thatduct 654 may be formed so as to pass through the interior ofproximal housing 638 and abouttissue separating member 644.Duct 654 thereby allows an operator to select the size ofcannula window 642 and thereby precisely control the size of operatingspace 28 created by the extension of tissue-separatingmember 644.

While tissue-separatingmember 644 is shown as depicted in FIG. 40a as an elongate wire having a circular cross-section, it is contemplated by the present invention that the actual cross section of tissue-separatingmember 644 may be formed so as to favor buckling in the direction of arrow I whenfree end 644b is moved in the direction of arrow G towardsblunt nose 632. FIGS. 40b-d show alternative cross-sections oftissue dissecting member 644 which may enhance buckling in the desired manner. Figure B depicts a crescent shape cross section in which anouter surface 644d faces towardscannula window 642. FIG. 40 depicts an oval cross sectional shape having a first cross sectional axis 644e and a second longer crosssectional axis 644f. The guidewire of FIG. 40c positions anouter surface 644d facing towardscannula window 642 and buckles about the longer crosssectional axis 644f. FIGS. 40d-e show a tissue-separatingmember 644 having ahelical thread 644g formed therealong which assists in the separation of adjacent tissue layers 12 and 16. It is also contemplated by the present invention thatdevice 630 may provide an elongateinterior wall 650 extending withincannula interior 641 adjacent to tissue-separatingmember 644 so as to prevent buckling in an unintended direction.Interior wall 650 desirably further provides a bowedsurface 652 extending against tissue-separatingmember 644 to further predispose buckling in a desired manner.

It is further contemplated that tissue-separatingdevice 630 may create an operatingspace 28 extending to opposite sides ofguidewire 18. After having opened a portion of operatingspace 28 to one side ofguidewire 18, tissue-separatingmember 644 may be retracted throughcannula window 642 and tissue-separatingdevice 630 may then be rotated 180 degrees about its longitudinal axis l. Once so rotated, tissue-separatingmember 644 may again be extended throughcannula window 642 as before to thereby enlarge operatingspace 28.

Alternatively, as shown in FIGS. 44-45, the present invention contemplates a dual-extending tissue-separatingdevice 660 having a first elongatetissue separating member 661 which may be extended simultaneously with, and oppositely to, second tissue separating member 662. Tissue-separatingdevice 660 incorporates many of the same features as tissue-separatingdevice 630 and conforms to the general design ofcannula 24 by providing ablunt nose 664 at one end of anelongate cannula wall 666 having aguidewire conduit 668 extending therealong and throughblunt nose 664.Tissue separating device 660 includes aproximal housing 670accommodating guidewire conduit 668 and first and seconddissection member passageways 672a and 672b.Cannula wall 666 defines both a cannula interior 673 and a first and second oppositely-disposedelongate windows 674a and 674b extending fromhousing 670 towardsblunt nose 664. During use,proximal housing 670 desirably extends fromgap 34 through theabdominal wall 12 and is exposed to, and accessible by, a surgeon. Tissue-separatingdevice 660 accommodatesretractable sheath 64, shown in phantom lines, so as to provide easier insertion thereof intogap 34.Sheath 64 may be retracted fromblunt nose 664 and overhousing 670 so as to expose tissue-separatingmembers 661 and 662. Tissue-separatingdevice 660 may be formed having a very small diameter in that it need only accommodateguidewire 18 and a similarly-sized tissue-separatingmembers 661 and 662. While it is contemplated thattissue separating device 660 has an external diameter of about 10 millimeters, it is also contemplated that the diameter may be about 5 millimeters and preferably about 2 millimeters.

Tissue-separatingmembers 661 and 662 extend from anchoredends 661a and 662a atblunt nose 664 through respectivedissection member passageways 672a and 672b ofhousing 670 tofree ends 661b and 662b and includebody portions 661c and 662c extending therebetween, respectively. Anchored ends 661a and 662a may be conventionally fixed within receiving cavities 646a and 646b defined by base surface 680 ofblunt nose 664 or otherwise positioned thereadjacent so as to be flexible thereabout.Body portions 661c and 662c are extendable and retractable throughwindows 674a and 674b, respectively, by actuation offree end 661b and 662b in the direction of arrows G and H. Tissue-separatingmembers 661 and 662 are desirably formed of a flexible yet resilient material such as stainless steel or a suitable surgical plastic such thatbody portions 661c and 662c buckle and extend throughcannula windows 674a and 674b. As free ends 661b and 662b are moved further in the direction of arrow G,body portions 661c and 662c buckle further and extend in the direction of arrow I away fromcannula wall 666 so as to pass between and separate the adjacent tissue layers 12 and 16 and thereby define operatingspace 28 of the desired dimensions.

It is contemplated that tissueseparation using device 660 may require a reciprocating motion offree end 661a and 662a in the directions of arrows G and H so as to deflectbody portions 661c and 662c in the directions of arrows I and J such that with ever increasing stroke lengths in the direction of arrow G will cause a larger deflections oftissue separating members 661 and 662 to thereby increase the size of the opened operatingspace 28. It is further contemplated that an external excitation force such as a radio frequency vibration may be applied to tissue-separatingmembers 661 and 662 to further assist in separating adjacent tissue layers 12 and 16. As withdevice 600, a surgeon may apply light pressure with one hand on the patient's abdomen to help maintain the buckling of tissue-separatingmembers 661 and 662 within the plane between the adjacent tissue layers 12 and 16.

The present invention also contemplates providing a tissue-separating device formed from a shape memory alloy, such as nitinol, through a small diameter cannula. Referring now to FIGS. 46-49, the present invention provides atissue dissection device 700 incorporatingcannula 24 and delivering atissue dissecting bar 702 withindelivery cavity 76.Tissue dissecting bar 702 desirably includes ablunt tip 704 at afree end 706 thereof, ashape memory elbow 708 deliverable in a linear configuration as shown in FIG. 46, and anelongate blade body 710 extending therebetween. Bar 702 also includes anelongate pusher rod 712 oppositely positioned acrosselbow 708 fromblade body 710 and extending outaccess aperture 44 ofcannula 24.

Bar 702 is deliverable in a fully martensitic state defined by the linear configuration shown in FIG. 46.Bar 702 is formed of a shape memory alloy composition having an austenitic start temperature slightly below that of body temperature. Afterbar 702 is delivered withingap 34, body heat will activate bar 702 to assume an austenitic configuration in whichelbow 708 deflects to positiontip 704 andblade body 710 exteriorly ofcannula window 52. Elbow 708 desirably assumes a right-angle configuration so as to extendblade body 710 substantially orthogonal topusher rod 712, as shown in FIG. 47. Extension ofblade body 710 to the right-angle austenitic configuration will simultaneously separate a portion of adjacent tissue layers 12 and 16. Onceblade body 710 is fully extended, the surgeon may form operatingspace 28 by pushing and pulling onpusher rod 712 in the directions of arrows L and M.

After operatingspace 28 has been formed,blade body 710 may be retracted throughwindow 52 by continued pulling onpusher rod 712 in a withdrawal direction shown by arrow L. Whileblade 702 is sufficiently rigid to withstand distortion while separating adjacent tissue layers 12 and 16,withdrawal forces blade 702 to deflect againstcannula wall 48 to a sufficiently linear alignment for withdrawal ofdevice 700 from operatingspace 28.

FIGS. 48-49 show analternate embodiment 740 of tissue-separatingdevice 700.Device 740 incorporatescannula 24 and delivers a tissue-separating blade 742 for separating adjacent tissue layers 12 and 16.Blade 742 is formed of a suitable shape memory alloy and is deliverable in a martensitic state withindelivery cavity 72 and is expandable in an austenitic state to extend to radially opposite directions between adjacent tissue layers 12 and 16.Blade 742 includes a first elongate separatingmember 744 and a second elongate separatingmember 746 extending from thedistal end 748a of apusher rod 748. In the martensitic state, separatingmembers 744 and 746 are deflected aboutdistal end 748a into parallel alignment withpusher rod 748.Blade 742 is desirably formed having an austenitic start temperature slightly below body temperature so as to expand as shown in FIG. 42 after delivery withingap 34. As further seen in FIG. 49, once separatingmembers 744 and 746 are fully extended, a surgeon may push and pull on afree end 748b ofpusher rod 748 in the direction of arrows M and N so as to separate adjacent tissue layers 12 and 16 and thereby define operatingspace 28. Once operating space is fully formed,blade 742 may be withdrawn back intodelivery cavity 76 by pullingpusher rod 748 in a withdrawal direction shown by arrowN. Separating members 744 and 746 are then forced to deflect aboutdistal end 748a bycannula wall 48 until fully withindelivery cavity 76, at whichtime device 740 may be withdrawn from operatingspace 28.

FIGS. 50-54 illustrate yet anothertissue separating device 760 of the present invention.Tissue separating device 760 incorporatescannula 24 and delivers first and secondtissue separating blades 762 and 764 for separating adjacent tissue layers 12 and 16.Blade 762 and 764 are formed of a rigid material such as metal or a suitably rigid surgical plastic.Blade 762 and 764 are elongate members having aproximal end 762a and 764a and adistal end 762b and 764b, respectively.Blade 762 and 764 pivot aboutproximal end 762a and 764a from a stored configuration enclosed withincannula 24 to an extended configuration projecting between adjacent tissue layers 12 and 16. As shown in FIG. 51,blade 762 and 764 pivot about apivot pin 766 affixed to apivot base 768 of ablade support 770.Blade support 770 further provides a transversely orientedblade stop 772 including ablade stop surface 773adjacent pivot pin 766.Blade stop surface 773 prevents over rotation ofblades 762 and 764 when extended between adjacent tissue layers 12 and 16.

Tissue separating device 760 further includes an elongatehollow guide sleeve 786 affixed aboutblade support 770 so as to provide a bushing for the sliding extension and retraction of anelongate actuating rod 774 therethrough. The distal end 770a of actuatingrod 774 includes a transversely-extendingdeployment wedge 776 having aplanar face 777 in facing opposition to blade stopsurface 773.Actuating rod 774 andblade support 770 extend through the interior space 779 of a rigidouter sleeve 780 having arim 782.Tissue separating device 760 defines an operatingwindow 784 betweenrim 782 ofsleeve 780 andblunt nose 40 ofcannula 24. Operatingwindow 784 communicates withdelivery cavity 76.Rim 782 andoperating window 784 are both desirably unveiled assheath 64 is withdrawn in the direction of arrow A away fromblunt tip 40.Blade stop 772 is positionable withincavity 785 so thatblades 762 and 764 may be extended and retracted throughoperating window 784, as will be discussed hereinbelow.

After deliveringdevice 760 intogap 34 between tissue layers 12 and 16, the operator retractssheath 64 away fromblunt nose 40 in the direction of arrow O to exposeoperating window 784. In its delivered configuration, actuatingrod 774 is positioned in an extended configuration wherebydeployment wedge 776 is positioned betweendistal ends 762b and 764b ofblades 762 and 764, as shown in FIG. 50. The operator then retractsmember 774 in the direction of arrow A so as to pulldeployment wedge 776 in sliding engagement with the convergingblades 762 and 764, causingblades 762 and 764 to pivot away from each other aboutpivot pin 766. Continued retraction ofdeployment wedge 776 in the direction of arrow O forces the deployment ofblades 762 and 764 throughoperating window 784 to a deployed configuration as shown in FIG. 53. Deployment ofblades 762 and 764 separates adjacent tissue layers 12 and 16 so as to form operatingcavity 28adjacent window 784. Retraction ofmembers 774 and 776 is complete whenplanar face 777 ofmember 776 pinsproximal end 762a and 764a ofblade 762 and 764 againstblade support surface 773 so thatblades 762 and 764 extend transversely fromdevice 760.Blades 762 and 764 may be held in this extended configuration by maintaining their compression betweensurfaces 777 and 773.

The operator may then continue to form operatingcavity 28 by extendingblade support 770 andmember 774 in the direction of arrow P towardsblunt nose 40.Blades 762 and 764 andoperating window 784 are desirably selected with sufficient dimensions that their deployment throughoperating window 784 and subsequent advancement along the longitudinal expanse of operatingwindow 784 will form anoperating cavity 28 of the desired dimensions. It is also contemplated by the present invention thatdevice 760 itself may be moved along theguidewire 17 in the directions of arrows O and P withblades 762 and 764 deployed so as to form anoperating cavity 28 having a longitudinal extent greater than that provided by operatingwindow 784.

Referring now to FIG. 54, after the creation of operatingspace 28,blade 762 and 764 may retracted throughwindow 784 in the following manner. An operator positions blade stop 772adjacent rim 782 oftube 780. The operator then extends actuatingrod 774 in the direction of arrow P untildeployment wedge 776 is positioned adjacentblunt nose 40. While maintaining the relative displacement ofdeployment wedge 776 fromblade stop 772, the operator retracts bothblade support 770 andactuating rod 774 in the direction of arrow O. Continued retraction in the direction of arrow O forces bothblades 762 and 764 againsttube rim 782 and their subsequent counter-rotation aboutpivot pin 766 and towardsdeployment wedge 774. Onceblade 762 and 764 have been retracted throughoperating window 784 the operator may withdrawdevice 760 out of the patient throughinsertion puncture 36.

4. Mesh and Delivery

Each of the tissue dissection devices and methods of the present invention may provide thenecessary operating space 28 in which a porous surgicalprosthetic mesh 30 may be emplaced to cover an operating site such as aherniated region 14. With reference to FIGS. 55-65, the present invention contemplates that theprosthetic mesh 30 may be either delivered by aballoon dissection device 60 of the present invention simultaneously with the formation of operatingspace 28, delivered by a second balloon device, or delivered by an alternate means which takes advantage of the operatingspace 28 previously created by a tissue-dissection device.

Prosthetic mesh 30 is desirably a thin porous surgical mesh which may be emplaced over the herniatedregion 14. Thepores 900 of theprosthetic mesh 30 permit tissue ingrowth therethrough, enabling the mesh to be assimilated by the body so as to form a new tissue layer over the rupture in the herniatedregion 14.Prosthetic mesh 30 further provides aperimetrical edge 902 defining a boundary providing sufficient overlap of the herniated region. While the art has seen many examples of prosthetic meshes suitable for surgical implantation, one particularly useful thin prosthetic mesh is disclosed by U.S. patent application Ser. No. 08/905,529 presently assigned to Meadox Medicals, Inc., a subsidiary of the present assignee.

A. Mesh Separable from Balloon

Prosthetic mesh 30 may be delivered to operatingspace 28 either simultaneously with the creation thereof by the expansion of a tissue-separating balloon of the present invention or by inflation of a subsequent mesh-delivery balloon 874 after the creation of operatingspace 28. While reference is made to a mesh-delivery balloon 874, the present invention contemplates that each of the tissue-separating balloons of the present invention may be utilized for delivery ofprosthetic mesh 30 as will be described hereinbelow. For the sake of simplicity,only balloon 874 will be called out in the following description.

Referring to FIGS. 55 and 56,prosthetic mesh 30 is desirably detachably attached across one major surface of aballoon 874 of the present invention and deliverable withballoon 874 by ahollow cannula 24 of the present invention. Asballoon 874 is inflated,prosthetic mesh 30 expands from its delivered configuration to a substantially planar configuration to be attached to theabdominal wall 12 by such conventional means as suturing or stapling or the like and then detached fromballoon 874 so as to remain in place over the herniatedregion 14.Balloon 874 may then be drained of the inflating fluid so as to enable easier extraction through one of the puncture holes 36 or 38. Draining of the inflating fluid may be accomplished by a combination of suction of the fluid throughfluid conduit 72 and puncturing ofballoon 874 so as to enable the fluid to leak therefrom.

B. Mesh Conformal with Balloon

The present invention also contemplates forming tissue-separatingballoon 874 of the present invention to be separable fromfluid conduit 72 and thereby emplaceable to remain over themyopectineal orifice 32 with the expandedprosthetic mesh 30. Referring still to FIGS. 57 and 58 and with additional reference to FIG. 58a, the present invention contemplates delivering a porous surgicalprosthetic mesh 30 conformal with a tissue-separatingballoon 874 of the present invention that is separable fromfluid conduit 72 so thatballoon 874 andprosthetic mesh 30 may be left in place over themyopectineal orifice 32. While reference is made to a mesh-delivery balloon 874, the present invention contemplates that each of the tissue-separating balloons of the present invention may be provided as emplaceable delivery balloons. For the sake of simplicity,only balloon 874 will be called out in the following description.Prosthetic mesh 30 is desirably laminated toballoon 874, althoughprosthetic mesh 30 may be adhered to balloon 874 by any means known in the art. Additionally,prosthetic mesh 30 is desirably laminated to balloon 874 at a number of distinct locations 904 along theperimetrical edge 902 thereof so as to maximize the number ofpores 900 available for immediate tissue ingrowth once emplaced. Whileprosthetic mesh 30 is desirably adhered to balloon 874 only along itsperimetrical edge 902 whenballoon 874 is formed in accordance with tissue-separatingballoon 374, other balloons of the present invention would also permit lamination at locations across a major surface thereof.

Emplacement ofballoon 874 is desirably provided by modifyingfluid conduit 72. As shown in FIG. 55a,fluid conduit 72 is severed adjacent to balloon 874 so as to provide a distal conduit end 72a and aballoon conduit end 72b.Balloon conduit end 72b is contiguous withballoon 874 and includes an inner passageway communicating with the balloon interior. An elongatehollow connector sleeve 890 is provided for joining conduit ends 72a and 72b in fluid communication.Sleeve 890 includes a hollowcylindrical wall 891 having a proximal end 890a, a distal end 890b and an elongatecylindrical wall 892 extending therebetween.Cylindrical wall 892 includes an outer surface 894a and a cylindricalinner surface 894b defining an elongate fluid passageway 896 throughsleeve 890. Outer surface 894a includes anannular depression 898.Sleeve 890 is internally received within both conduit ends 72a and 72b.Conduit end 72 is adhered or otherwise affixed to outer surface 892a whileconduit end 72b is removably fitted thereabout. A removable retaining means such as o-ring 899 is positioned overconduit end 72b in registry withannular depression 898 so as to provide a fluid tight and releasable connection betweenconduit end 72b andsleeve 890.

As tissue-separatingballoon 874 is to be emplaced with and remain with theprosthetic mesh 30,balloon 874 is desirably formed from a biodegradable material that will decompose and be absorbed by the body as tissue grows through the pores of the emplacedprosthetic mesh 30. The terms "biodegradable" and "bioabsorbable" as used herein are given common meaning for the present invention and relate to the ability to be degraded by processes involving biological conditions, such as those present in the bodies of humans or other animals. More specifically, this term indicates the physical or chemical breaking down of the polymer into smaller units which are preferably innocuous, non-toxic, and are readily eliminated by the body.Balloon 874 therefore allows a mesh to be delivered simultaneously with the creation of operatingspace 28. It is contemplated that additional access ports may be provided so that additional small diameter cannulas may be inserted into operatingspace 28 for suturingprosthetic mesh 30 to theabdominal wall 12.

Alternatively, the present invention further contemplates thatprosthetic mesh 30 may be delivered by an emplaceabletissue separating balloon 1074 wherein theprosthetic mesh 30 forms one major surface of that balloon. As shown in FIGS. 57-58,balloon 1074 may be formed in accordance with any of the balloons of the present invention providing a suitable major surface.Tissue separating balloon 1074 includes a firstmajor surface 1078 formed by a porous surgicalprosthetic mesh 30 having a plurality ofpores 900 sealed fluid tight by abiodegradable filler 910.Balloon 1074 may perform the function of tissue-dissection simultaneously with the positioning ofprosthetic mesh 30 over the herniatedregion 14.Balloon 1074 may be separated fromfluid conduit 1072 for emplacement within operatingspace 28. A surgeon may suture, adhere, or otherwise affixballoon 1074 or justmajor surface 1078 to theabdominal wall 12 after the dissection and ligation of the hernia sac. Thereafter, thebiodegradable material 910 filling thepores 900 ofprosthetic mesh 30 will be absorbed by the body so as to expose thepores 900 and thereby provide for tissue ingrowth therethrough. The remainder ofballoon 1074, being similarly made of a biodegradable material, will similarly dissolve for absorption by the body. As it is desirable to first exposepores 900 ofprosthetic mesh 30 prior to assimilatingmesh 30 within the body,biodegradable material 910 filling thepores 900 ofprosthetic mesh 30 will be selected so as to break down prior to the biodegradable material formingprosthetic mesh 30 breaking down.

C. Mesh separately provided by guidewire

Referring now to FIGS. 59-65, the present invention also contemplates delivering a surgical mesh to an operatingspace 28 previously formed by a tissue dissection device. FIGS. 59, 62 and 64 depict amesh delivery device 1100 for deliveringprosthetic mesh 30 intooperating space 28.Mesh delivery device 1100 is an elongate device having ablunt nose 1102 and atubular body portion 1104 at opposite ends of a centrally locatedguidewire conduit 1106.Blunt nose 1102,body portion 1104 andguidewire conduit 1106 define a longitudinally extending guidewire passageway 1108 throughdevice 1100 for accommodatingguidewire 18.Device 1100 is formed of a rigid material such as metal or a suitable surgical plastic.Guidewire conduit 1106 is desirably centrally located so as to serve the dual purposes of accommodatingguidewire 18 throughdevice 1100 and to serve as a deployment axle for deployably wrapping aprosthetic mesh 30 thereabout. As shown in FIG. 59,device 1100 includes aretractable sheath 1110, shown by phantom lines, and a circumferential retaining means such as anelastic band 1112 positioned aboutprosthetic mesh 30 so as to maintain the furled configuration ofprosthetic mesh 30 aboutguidewire conduit 1106 prior to mesh deployment.

Prosthetic mesh 30 is desirably a porous meshmaterial providing pores 900 for promoting tissue ingrowth therethrough and may be formed of a biodegradable material to be absorbed through the body after forming a new tissue layer over the herniated region. One particularly useful prosthetic mesh is disclosed by U.S. patent application Ser. No. 08/905,529 presently assigned to Meadox Medicals, Inc., a subsidiary of the present assignee and is incorporated by reference herein. FIGS. 60 and 61 depict two possible configurations for deployably wrappingprosthetic mesh 30 aboutguidewire conduit 1106. FIG. 60 depicts a configuration whereby oneedge 902a ofprosthetic mesh 30 is placed onguidewire 1106 and thenprosthetic mesh 30 is then simply spooled thereabout. FIG. 61 depicts an alternate delivery configuration forprosthetic mesh 30 wherebyprosthetic mesh 30 is longitudinally folded to provide acrease 912. While maintainingprosthetic mesh 30 in the folded configuration,crease 912 is positionedadjacent guidewire conduit 1106 andprosthetic mesh 30 is then spooled thereabout so as to desirably provideopposed edges 902a and 902b to diametrically opposite sides ofguidewire conduit 1106.

With reference to FIGS. 63 and 65,device 1100 may be delivered alongguidewire 18 to a location within operatingspace 28. The operator then retractssheath 1110 in the direction of arrow a so as to exposeprosthetic mesh 30 to operatingspace 28. The operator then desirably provides an insufflation gas, such as carbon dioxide, so as to inflateoperating space 28 for prosthesis deployment. Insufflation may be accomplished by any means well-known in the art. As shown in FIGS. 62 and 63, whereinguidewire 18 is desirably provided along one edge of operatingspace 28, the operator provides an entry port on the opposite side of operatingspace 28 for introducing anelongate unfurling probe 1120.Probe 1120 desirably includes transversely extendingfinger 1122 for grabbing and manipulatingprosthetic mesh 30.Probe 1120 may also be used for pushingretainer 1112 clear ofprosthetic mesh 30. The operator grabs the free edge 90b ofprosthetic mesh 30 withprobe finger 1122. The operator desirably provides a secondelongate unfurling probe 1124 having a transversely-extendingfinger 1126 so that opposing ends of the exposed edge 90b ofprosthetic mesh 30 may be simultaneously pulled so as to unfurlprosthetic mesh 30 fromdevice 1100 while simultaneously positioningprosthetic mesh 30 within operatingspace 28.Prosthetic mesh 30 may then be sutured or stapled in place over the herniatedregion 14.

FIGS. 64 and 65 depict the unfurling ofprosthetic mesh 30 when it is furled aboutguidewire conduit 1106 as shown in FIG. 60. Withprosthetic mesh 30 so furled,device 1100 is desirably provided along aguidewire 18 centrally positioned within operatingspace 28. The operator insufflates operatingspace 28 using conventional techniques and provides access ports 1140 and 1142 transversely spaced fromdevice 1100 for introducingdeployment prongs 1120a and 1120b. With this configuration the operator may grab the opposingedges 902a and 902b ofprosthetic mesh 30 and pull each in opposite directions to thereby unfurl the prosthesis within operatingspace 28. The operator may useprongs 1120a and 1120b to fully deploy the prosthesis prior to suturing or stapling the prosthesis in place over the herniatedregion 14.

Referring to FIG. 66, it is also contemplated by the present invention to provide aprosthetic mesh 30 rolled within theinterior passageway 1202 of anelongate delivery needle 1200.Delivery needle 1200 includes anelongate ejection plunger 1204 slidable withinpassageway 1202 towards anejection end 1200a ofneedle 1200.Ejection end 1200a may be provided withinoperating space 28 so thatprosthetic mesh 30 may be ejected thereinto by pushingplunger 1204 and unfurled by the operator. It is further contemplated thatprosthetic mesh 30 may include a self-opening element for automatically deploying within operatingspace 28 over the herniatedregion 14.

Regardless of the method used for deploying a prosthesis of the present invention it is felt that reinforcement in this area with a surgical mesh allows intra-abdominal pressure to assist in securing the inlayed prosthesis to the pelvic floor rather than acting as a factor in recurrence. After mesh placement, the peritoneum becomes nondistensible, and thus there is no need for hernia defect closure.

While the present invention has been shown and described in detail above, it will be clear to the person skilled in the art that changes and modifications may be made without departing from the spirit and scope of the invention. That which is set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined by the following claims.

Claims (9)

What is claimed is:

1. A device for creating an operating cavity in a mammal between two adjacent layers of tissue adjacent to an operating area of one of said layers of tissue, said device comprising:

a guidewire-deliverable dissecting member, said dissecting member being deliverable to a deployment area adjacent an operating site within an elongate hollow cannula defining an elongate interior lumen, an access port communicating with said interior lumen and accessible outside the body of a patient, and an elongate deployment aperture communicating with said interior lumen and accessible to said deployment area;

said dissecting member including an elongate dissecting tip extendable from said elongate aperture of said dissecting member between said adjacent layers of tissue; and

actuator means for retractably extending said dissecting tip from said dissecting member to separate layers of tissue adjacent the operating area to form the operating cavity.

2. The device of claim 1, wherein said dissecting tip is provided by an elongate flexible wire extending through said interior lumen and having a first end anchored to the blunt nose and an opposed second end extending through said access port exterior said interior lumen, whereby said second end of said flexible wire may be extended through said access port towards the blunt nose so as to buckle the wire outwardly through the cannula window to separate the adjacent tissue layers in forming the operating cavity.

3. The device of claim 2, wherein said flexible wire includes a cross-sectional shape which favors buckling from the interior lumen towards the cannula window.

4. The device of claim 3, wherein said flexible wire includes a crescent-shaped cross-section.

5. The device of claim 3, wherein said flexible wire includes a cross-sectional shape defined along a first major axis and a second transverse major axis, whereby the dimension of said cross-section along said second major axis is longer than the dimension of the cross-section along the first major axis so as to favor buckling about the second major axis.

6. The device of claim 2, wherein said flexible wire includes projections along the surface thereof which facilitate tissue separation.

7. The device of claim 6, wherein the surface of said flexible wire includes a helical thread formed thereon.

8. The device of claim 2, wherein said interior lumen includes a longitudinally centrally located protrusion formed on the cannula wall in facing opposition to the window and adjacent the flexible wire so as to instigate buckling of the wire towards the window.

9. The device of claim 2, wherein said cannula defines a second elongate deployment aperture communicating to the opposite direction from the interior lumen as the first deployment aperture, said device further including a second elongate flexible wire extending through said interior lumen having a first end anchored to said blunt nose and an opposed second end extending through said access aperture, said second flexible wire being extendable through said second deployment aperture, whereby simultaneous extension of said first and second flexible wires simultaneously forms an operating space to either side of the guidewire.

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